LOS ANGELES, CA—MARCH 2, 2013—Dale Robertson, whose horse expertise, Oklahoma roots and handsome looks helped him win cowboy roles in 1950s and '60s, has died at age 89, his wife said Thursday.

Robertson was diagnosed with Stage 4 cancer just last week while being treated for pneumonia at Scripps Memorial Hospital in La Jolla, California. He died Tuesday.

"He always said he lived two or three lifetimes," Susan Robertson said. "He was in Hollywood when it was great."

Dale and his brother Chet owned the operated Haymaker Sale Company in Oklahoma City for many year's as well as Haymaker Farms near Yukon. Following Chet's death, the sale company was purchased by a group of prominent horsemen and renamed Heritage Place Sale Company.

The Robertson's bred and raced Champion and leading sire Rebel Cause and Dale was a partner in champion aged stallion Johnny Vittoro in 1983.

Robertson's acting career began after a movie scout saw a photo of him in a Hollywood photo shop's display window. He had the portrait taken to send to his mother while he was stationed at an Army post in California, according to his official biography.

He acted in several uncredited movie roles in 1948 after he left the Army, leading to his role as the outlaw Jesse James in "Fighting Man of the Plains" in 1949.

Robertson starred in the TV Western series "Tales of Wells Fargo" from 1957 through 1962, riding a horse named Jubilee.

He and his wife raised horses in Oklahoma until moving to a San Diego suburb last summer, Susan Robertson said.

He hosted, along with Ronald Reagan, episodes of "Death Valley Days" during the 1960s. Film roles, also mostly Westerns, included "Devil's Canyon," "Sitting Bull," and "Dakota Incident." In the 1980s, Robertson was a regular on the first season of "Dynasty," and acted in episodes of "The Love Boat," "Murder, She Wrote" and "Dallas."

His last role came in two episodes of the TV series "Harts of the West" in 1993.